Method for the purification of petroleum mahogany sulphonates



Patented July 18, 1939 p 2 15 117 UNITE!) T PATENT OFFICE .METHOD FOR THE PURIFICATION OF PETROLEUM MAHOGANY SULPHONATES Manuel Blumer, Butler, Pa., assignor to L. Sonneborn Sons, Inc., .a corporation of Delaware No Drawing. Application January 19, 1937',

I a Serial No. 121,288

'12 Claims. (Cl. 260-504)- This invention relates to a new and useful brevity simply as mahogany sulphonate" or method for the purification of petroleum mahog- "mahogany sulphonates. any sulphonates. One object of my invention comprises inter The conventional refining treatment of ceralia the removal 'of inorganic salts from crude tain lubricating oil distillates derived from pemahogany sulphonate stock as it is customarily I troleum includes the application of fuming sulobtained in the acid treatment of petroleum phuric acid. This reacts with the oil, producing distillates and containing varying amounts of a black sludge containing 'unreacted sulphuric entrained oil. The oil content of such crude acid and certain types of sulphonic acids. stock is usually up to 40% or more, while the 10 Though the concentration of S: in the fuming inorganic salts, particularly sulphates and 8111- acid may vary considerably, a fuming acid phites, are as a rule present in amounts of apis employed in the majority of cases. As a reproximately 9% or higher. For many purposes suit of the high degree of sulphonation obtained it is not only desirable but requisite to substanin the acid treatment, a considerable amount of tially remove these admixed-inorganic salts from 5 sulphonic acids is produced. These are printhe mahogany sulphonate stock. The removal 16 cipally of two types, that is, the so-called waterof the entrained oil, in the majority of cases, is soluble type predominantly contained in the not necessary and its presence is in some insludge and the so-called oil-soluble type prestances even desirable. dominantly found in the oil to the extent of a I have discovered that a mahogany sulphonate 20 few percent. The acid application is regulated stock containing entrained oil can be obtained in 20 in the manner well known in the art to produce a substantially pure condition from crude mathe desired sulphonation reaction and in genhogany sulphon'ate stock by the use of butyl ai-- eral temperatures not exceeding 140 F. are precohol in the presence of water. In the practical ferred. The acids contained in the sludge, while application of my method the crude mahogany limitedly soluble, if atall, in hydrocarbon oils, sulphonate stock containing entrained oil is '25- A are highly water-soluble, imparting, to their contacted with the butyl alcohol and a certain aqueous solution a dark-green color, and being amount of water as thoroughly as possible and for this reason generally referred to as "green preferably with the aid of agitation; though not petroleum sulphonic acids. The acids left in necessary it is of advantage thereafter to heat solution in the oil impart a reddish color to the the resulting mix to from 120 to 130 F. for the 30 oil and for this reason are generally referred purpose of facilitating the removal of the inorto as mahogany petroleum sulphonic acids. ganic salts from the mahogany sulphonate stock. After the separation of the oil from the acid The free alkali is then neutralized and theme!!- sludge the mahogany sulphonic acids are usually tralized mix left to settle until two layers have recovered from the oil in the form of their salts formed. The upper or oily layer is primarily as in accordance with ordinary refining methods composed of mahogany sulphonate, oil and butyl comprising conversion oi' the acids into salts by alcohol. Whe ea t e lower 0 aqueous layer direct neutralization of the acid treated oil folcomprises Predominantly an 8111180115 Salt 80 lowed by suitable extraction. These salts or the inorganic s ts sin y p e- 40 mahogany sulphonates constitute a valuable bysentthe crude mahogany sulphonate smk 40 of petroleum we used 322213832;iiitihiifiiolfiit.from X22 3: of purposes but primarily as m the 'oily layer the butyl alcohol is removed from The mahogany sulphonic acids or mahogany i mahogglny iulphonate S i by g sulphonates constitute a material well defined in an may recwere I v the alcohol has been flashed on; the mahogany its W 9 and propertles though as yet sulphonate stock is obtained substantially pure, known Its 5 assumed F that is, substantially free from inorganic salts prise a series of closely related sulphonic acids in excess f 3% and in most instances in excess or'sulphonates as the case may bewith a varyin of 1%, which in the majority of cases is sufli- 5 number of sulpho groups. Inasmuch, however, ciently pure for commercial purposes. as the material obtained in the refining of pe- In accordance with my invention it is of adtroleum oils is substantially uniform and well vantage to control the pH of the mix and I have identifiable I have termed and will refer to the found that if the pH appreciably exceeds 9 (beneutralized sulphonic acids for the purpose of ing on the alkaline side) it is highly diillcult in u large scale operations and frequently impossible to obtain a product substantially free from inorganic salts content in excess of 3%. where-- as a pH of 9 or below and above 3 and preferably'a pH of or'between '7 and 3 yields a substantially pure end product. This becomes of particular importance with regard to the extent of neutralization with a suitable acid to which the mahogany sulphonate stock must be subjected for the successful purification, should it possess too high a degree of alkalinity, which is usually the case as the result of the freealkali normally present therein. A neutralization with phenol phthalein as indicator will show a neutral point at a pH of approximately 7.5 to. 8 and .sometimeseven as high as 9. If methyl red or methyl orange are used.as indicator the 4 end pointof the neutralization appears at a pH of 6 to '1 or of 3 to 4 respectively. A neutralization with the last mentioned indicators therefore will be preferable as yielding a product of still less salt content than the final product ob- 'tained when the neutralization has been eifected to the phenol phthalein end point.

A further advantage of the control of the pH within the indicated limits resides in the fact that it accelerates the speed with which the inorganic salts will be removed and the mix will stratify into layers. Within the range of pH specified this separation is considerably faster than at higher pH ranges.

. Concerning the proportions of butyl alcohol and water that I may use in accordance with my invention for the removal of the inorganic salts from a mahogany sulphonate stock containing entrained oil, I have found that satisfactory re.- sults can be obtained by maintaining a ratio of mahogany sulphonate stock plus entrained oil to butyl alcohol in excess of 0.5 and preferably between 2.0 and 3.0, a ratio of mahogany sulphonate stock plus entrained oil to water in excess of 0.5 and preferably between 1.5 and 6.0 and a ratio 'of butyl alcohol to water in excess of 0.5 and preferably between 0.8 and 4.0. For economical reasons, however, I prefer to use such proportions within the defined limits as will permit the' greatest concentration of mahogany sulphonate stock plus entrained oil and the least amount of alcohol; and have found it of advantage to utilize a ratio of mahogany sulphonate stock plus entrained oil to butyl alcohol of 2, a ratio of mahogany sulphonate stock plus entrained oil to water of 2 and a ratio of butyl alcohol to water of 1 which in percentage proportions is equivalent to mahogany sulphonate stock, plus entrained oil, 25% butyl alcohol and 25% water.

It is of course understood and within the purview of my invention that I may use the isomers of butyl alcohol, such as secondary and tertiary butyl alcohol and wherever I use the term butyl alcohol in the specification and claims I mean to include such isomers.

Though I prefer to neutralize the alkalinity present in the mahogany sulphonate stock after the addition of the alcohol and water, I may effectuate this neutralization before such addition and circumstances as well as particular practices may sometimes require this deviation from the preferred procedure.

The foregoing description is by way of illustration and not of limitation and I am not to be limited to any details but only by the appended claims in which I have endeavored to claim broadly all inherent novelty.

Iclaim: I 1. Method of purifying petroleum mahogany sulphonates containing entrained oil and inorganic salts which comprises contacting said impure sulphonates with a butyl alcohol and water in amount and ratio sumcient to thereby form a first liquid layer substantially free from-inorganic salts and consisting predominantly of butyl alcohol and mahogany sulphonate plus entrained oil and a second liquid layer consisting predominantly of an aqueous solution of said inorganic salts, thereafter separating saidfirst liquid layer from said second liquid layer and finally removing said butyl alcohol from said first liquid layer and recovering mahogany sulphonate plus entrained oil substantially free from inorganic salts.

2. Method'of purifying petroleum mahogany sulphonates containing entrained oil and inorganic salts which comprises contacting said inipure sulphonates with a butyl alcohol and water while substantially maintaining a pH range between 3.0 and 9.0, said butyl alcohol and said water being present in amount and ratio suillcient to thereby yield a first liquid layer substantially free from inorganic salts and consisting predominantly of butyl alcohol and mahogany sulphonate pure sulphonates with a butyl alcohol and water,

substantially maintaining a ratio of mahogany sulphonate containing entrained oil" and inorganic salts to butylalcohol between 2 and 3, to water between 1.5 and 6 and a ratio of butyl alcohol to water between 0.8 and 4.0, to thereby form a first liquid layer substantially free from inorganic salts and consisting predominantly of butyl alcohol and mahogany sulphonate plus entrained oil and a second liquid layer consisting predominantly of an aqueous solution of said inorganic salts, thereafter separating said first liquid layer from said second liquid layer and finally removing said butyl alcohol from said first liquid layer and recovering mahogany sulphonate plus entrained oil substantially free from inorganic salts.

5. Method of purifying petroleum mahogany sulphonates containing entrained oil and inorganic salts which comprises contacting said impure sulphonates with a butyl alcohol and water while substantially maintaining a pH range between 3.0 and 9.0, and a ratio of mahogany sulphonate containing entrained oil and inorganic salts to butyl alcohol between 2 and 3, to water between 1.5 and 6 and a ratio of butyl alcohol to water between 0.8 and 4.0, to thereby form a first liquid layer substantially free from inorganic'salts and consisting predominantly of butyl alcohol and mahogany sulphonate plus entrained oil and a second liquid layer consisting predominantly of an aqueous solution of said inorganic salts, thereafter separating said first liquid layer from said second liquid layer and finally removing said butyl alcohol from said first liquid layer-and recovering mahogany sulphonate plus entrained oil substantially free from inorganic salts.

6. Method in accordance with claim in which the pH range is substantially maintained between 3 and '7 and in which the ratio of mahogany sulphonate containii'i'fihtrained oil and inorganic salts to butyl alcohol and to water is 2 and the ratio of butyl alcohol to water is 1.

'7. Method of purifying petroleum mahogany sulphonates containing entrained oil and inorganic salts which comprises contacting said impure sulphonates with a butyl alcohol and water at a temperature of 120 to 130 F., said butyl alcohol and said water being present in amount and 15 ratio sufiicient tothereby yield a first liquid layer substantially free from inorganic salts and consisting predominantly of butyl alcohol and mahogany sulphonate plus entrained oil and a second liquid layer consisting predominantly of an aqueous solution of said inorganic salts, thereafter separating said first liquid layer from said second liquid layer and finally removing said butyl alcohol from said first liquid layer and recovering mahogany sulphonate plus entrained oil substantially free from inorganic salts.

8. Method of purifying petroleum mahogany sulphonates containing entrained oil and inorganic salts which comprises contacting said impure sulphonates with a butyl alcohol and water at a temperature of 120 to 130 F. while substantially maintaining a pH range between 3.0 and 9.0, said butyl alcohol and said water being present in amount and ratio suilicient to thereby yield a first liquid layer substantially free from inorganic salts and consisting predominantly of butyl alcohol and mahogany sulphonate plus entrained oil and a second liquid layer consisting predominantly of an aqueous solution of said inorganic salts, thereafter separating said first liquid layer from said second liquid layer and finally removing said butyl alcohol from said first liquid layer and recovering mahogany sulphonate plus entrained oil substantially free from inorganic salts.

9. Method in accordance with claim 8 in which said pH range is substantially maintained between 3.0 and 7.0. v

10. Method of purifying petroleum mahogany sulphonates containing entrained oil and inorganic salts which comprises contacting said impure sulphonates with a butyl alcohol and water at a temperature of 120 to 130 F., substantially maintaining a ratio of mahogany sulphonate containing entrained oil and inorganic salts to butyl alcohol between 2 and 3, to water between 1.5 and 6 and a ratio of butyl alcohol to water between 0.8 and 4.0, to thereby form a first liquid layer substantially free from inorganic salts and consisting predominantly of butyl alcohol and mahogany sulphonate plus entrained oil and a second liquid layer consisting predominantly of an aqueous solution of said inorganic salts, thereafter separating said first liquid layer from said second liquid layer and finally removing said butyl alcohol from said first liquid layer and recovering mahogany sulphonate plus entrained oil substantially free from inorganic salts.

11. Method of purifying petroleum mahogany sulphonates containing entrained oil and inorganic salts which comprises contacting said impure sulphonates with a butyl alcohol and water at a temperature of 120 to 130 F. while substan- 7 tially maintaining a pH range between 3.0 and 9.0, and a ratio of mahogany sulphonate containing entrained oil and inorganic salts to butyl alcohol between 2 and 3, to water between 1.5 and 6 and a ratio of butyl alcohol to water between 0.8 and 4.0, to thereby form a first liquid layer substantially free from inorganic salts and consisting predominantly of butyl alcohol and mahogany sulphonate plus entrained oil and a second liquid layer consisting predominantly of an aqueous solution of said inorganic salts, thereafter separating said first liquid layer from said second liquid layer and finally removing said butyl alcohol from said first liquid layer and recovering mahogany sulphonate plus entrained oil substantially free from inorganic salts.

12. Method in accordance with claim 11 in which the pH range is substantially maintained between 3 and 7 and in which the ratio of mahogany sulphonate containing entrained oil and inorganic salts to butyl alcohol and to water is 2 and the ratio of butyl alcohol to water is 1.

MANUEL BLUMER. 

